Falling prices on LEDs mean solid-state lighting is poised to displace bulbs, opening markets for connectors while altering wiring and electronic architectures.
The automotive industry is ramping up its adoption of LED lighting. Falling prices, improving brightness, and integration with next-generation electric and safety systems are making this once-niche lighting option a mainstream choice. However, this transition requires changes to several factors in wiring harnesses and connectors, which are simultaneously adapting to other evolving electronic architectures in vehicle design.
From a pure design point of view, LEDs enable far more freedom, making them a natural fit for the style-conscious car industry. On the outside of the car, LEDs are the core of sweeping lines for headlights and unusual styles for taillights. The solid-state devices also make it simple to angle light beams to illuminate side roadways when drivers are turning. In car interiors, their small size makes it easier to stick LEDs in many locations while also providing more freedom to use color.
Technologists also like this versatility, along with LEDs’ long lifetimes and compact sizes. However, employing solid-state lighting comes with design challenges. High light output means high power consumption. That makes cooling the headlight enclosures a major factor.
“Designers need a cooling mechanism. Many are putting openings on the top and/or bottom of the enclosure,” said Puneet Sinha, a project manager at Mentor Graphics. “Terminals are a big factor because heat impacts the intensity of LEDs.”
Automotive companies are concerned about the weight of wiring, while the companies that make harnesses are concerned with the growing complexity. One solution is to adopt a holistic approach that uses digital models of components and systems as well as digital files for the manufacturing equipment that will be used to build them.
Some major companies are beginning to adopt this strategy, sometimes called a model-based enterprise. This approach could transform the wiring harness business, which is sometimes seen as one of the last bastions of manual labor in the automotive and electronics industries.
“In model-based enterprises, companies can digitally capture the wiring harness design and combine that with the digital files that describe the complexities of manufacturing operations,” said Martin O’Brien, at Mentor Graphics’ Integrated Electrical Systems Division. “Then you can merge them and create the steps needed to build the harness.”
As LEDs expand in tandem with electric fueling and autonomous driving systems, strategic communication between these systems, along with careful design, is essential.
“Understanding how architectural elements work together includes components like connectors,” Gregory Rochowiak, head of core engineering at Yazaki, said at a recent Mentor Graphics event. “Understand how wiring is connected during development. Otherwise, you’ll get large boards with lots of wires and connectors.”
Connector suppliers are responding with products like ERNI’s MiniBridge Koshiri Security connector, unveiled earlier this year. Variants with two to 12 pins and current-carrying capacity extending up to 4 amps per contact boast a scoop-proof design that reduces the chance of damage. The connectors are designed for space-constrained applications with higher current demands than standard compact electronic devices, including: LED, LCD, and TFT displays, automotive headlights, handheld devices, and sensors.
Vendors are teaming up to address the growing demand for LEDs in automotive. TE Connectivity was a founding member of the ISELED Alliance, a consortium formed last year to develop LED-related products and solutions around an in-car LED lighting concept that integrates a smart LED driver with three color LEDs. Inova, NXP, Dominant Opto Technologies, and Pforzheim University were also founding members, and Valeo recently joined the consortium.
Growth rates are high. Market analysts at LEDinside said that the growth potential for LEDs in exterior lighting is “huge,” noting that less than 15% of today’s vehicles use LEDs. This transition could mean a global automotive LED market of $2.29 billion by 2020, representing a compound annual growth rate of 8% from 2015 to 2020. Volumes may grow to 3.67 billion pieces in 2020, up from 2.79 billion pieces 2015.
High-power LEDs for high- and low-beam headlights will see the highest growth, with a CAGR of 23% from 2015 to 2020. The high-power devices used in headlights, taillights, and other external applications remain higher-margin parts.
The changeover to LEDs is much farther along in the cabin. LEDs are being scattered throughout the interior to light up cup holders and door handles, and they’re also being used to provide mood lighting and backlights for instrument clusters, which will help drive some growth in volumes. However, revenues for interior LEDs will be flat to declining through 2020, the LEDinside report explained. That’s because prices of standard standard-power LEDs are plummeting.
The changeover from a range of lighting alternatives comes as the auto industry’s electronic architectures are evolving beyond the CAN networks that have dominated for several years. Automakers are starting to use Ethernet in the demanding safety systems that are being adopted as the industry drives towards autonomous driving. Ethernet also addresses the explosion of communications inside the cabin.
But even though a broad range of multiplexing schemes let automotive designers send more signals over fewer wires, the size of wiring harnesses continues to grow. The rise in safety sensors is a big reason. The expanding role of LEDs is another.
Together, all these factors will push the global automotive wiring harness market to $54.2 billion by 2021, analysts at Lucintel predict. That represents a CAGR of 6.3% from 2016 to 2021.
Solid-state lighting technology has only gone mainstream in the past decade, but its impressive growth and flexibility means LEDs — and the connectors and wiring systems they depend on — will be lighting the way for us for years to come.